Usage Tips:[Heavy Duty]: Made of ABS material with stable structure, this stucco/concrete wall hook providing a reassuring load weight up to 25 LBS [No Drilling Required]: These picture hangers are really easy to install with the auxiliary tool provided. Just need a hammer without drilling [Invisible Nails]: Not like ordinary nails, our wall hangers only leave unnoticeable pinholes after removal. No damage to the wall [Sundry Applicable Occasion]: The picture hanging kit can be used for hanging picture frame, mirror, clock and more. Compatible with different wall types like stucco/cement/concrete wall/plaster/drywall, but NOT for brick wall [Package Content]:40 PCS wall kooks with a storage box. The auxiliary tool like little handle and gradienter are also included color:White Material:ABS size:4 x 2 x 0.9cm Package Contents: 40 x No trace nail Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.